Tuesday, February 15, 2011

Prey Vulnerability can Influence Habitat Use

Foraging in the Landscape of Fear, the Predator’s Dilemma: Where Should I Hunt?John W. Laundré, Jesús M. M. Calderas and Lucina Hernández

Here is a good paper that I read recently. It appeared in the open ecology journal and is very fascinating in its implications. I am giving below the abstract as it is an open journal document.

Under predation risk, prey species are more abundant in areas of low predation risk even at the expense of forage quality. As a result two predictions are possible, 1) predators should choose to hunt in areas with fewer but easier to catch prey than areas where they are more abundant but harder to catch; and 2) the frequency of prey species in the diet of predators using low risk areas should be greater than, or at least equal to, the diet of predators using high risk areas. To test these two predictions, we used data on coyoteCanis latransabundance and diet composition from two habitats in the Chihuahuan Desert of Mexico that have different abundances of jackrabbits (Lepus californicus) and rodents. We used the number of coyote scats found in transects in the two areas to assess coyote abundance and analyzed the contents of these scats to determine diet composition. We found significantly more coyote scats/yr (22.6 ± 4.7 (SE) vs. 12.2 ± 2.4 scats/yr, d.f. = 7, pairedt= 3.80, P = 0.007) in the habitat with less jackrabbits and more rodents. However, the percent occurrence of jackrabbits (54.3 ± 6.7% vs. 60.1 ± 7.7%) and rodents (32.6 ± 6.5% vs. 30.1 ± 6.0%) in coyote scats did not differ between the two habitats. These results supported both the above cited predictions and the hypothesis that prey vulnerability can influence habitat use by coyotes.